Steam generator or water heater



Oct. 22, 1940. E, sp N 2,218,898

STEM GENERATOR 0R WATER HEATER Filed July 19, 1938 Patented Oct. 22,1940 STEAM GENERATOR OR WATER HEATER Edward Frank Spanner, Blackheath,London,

England Application Jul 19, 1938, Serial No. 220,094

4 Claims.

This invention relates to improvements in steam generators and waterheaters of thimble tube type, for waste heat recovery from Diesel engineexhaust gases, andhas for its object the production of units convenientfor installation and inspection suitable'and efficient for engines -,ofdifferent sizes delivering different volumes of gas, and very economicalin first cost, dimensions and weight. I :Waste heat boilers of thimbletube type for .use with Diesel engine exhaust gases must have:

(1) Sufficient thimble tube heating surface to recover all the heatavailable.

(2) Sufficient area for the passage of the gas to avoid undue backpressure.

(3) Provision for reducing this area as the gas cools down.

(4) Provision for easy access to both the water and gas sides of thethimble tube heating surface.

This invention satisfies all these various requirements much better thanthey can be satisfied by units of known practice by arranging that theflow of the gas through the thimble tube nests shall be controlled bythe disposition of a series of spiralled directional plates which can bealtered in position in the same tube nest so that a single unit can bemade effective for a range of engines having] different rates of exhaustgas output.

In the drawing:

Figure 1 shows a section through a unit in accordance with thisinvention and having inlet and outlet at the top of the boiler on thesame diameter, but off the centre.

Figure 2 shows a section through a unit having both inlet and outlet atthe top but one of them central.

Both of these units could be used upside down.

Figure 3 shows an arrangement of removable spiralled directional platessuitable for Figure 1.

Figure 4 shows an arrangement of removable spiralled directional platessuitable for a unit generally similar to that shown in Figure 1 i. e.havinginlet and outlet connections communicating with the annular spacebetween the centre cylinder and the tube plate, but having these twoconnections communicating with gas channels adjacent to one another.Such an arrangement might be more convenient in layout than that shownin Figure 3.

Figure 5 shows an arrangement of removable stepped directional platessuitable for a unit generally similar to that shown in Figure 1, buthaving the inlet and outlet gas connections com- Gil municating with gaschannels adjacent. to one another. 1:; Using-the same tube nest, theinvention enables either spiralled or stepped directional plates to berearranged to suit engines of different horsepower or of .different gasdischarge characteristiCS.

If, in certain cases, the rearrangement of-these plates tov suit adifferent engine causesrthe final gas channel .to lead in a downwardinsteadrot a preferred upward direction or vice versa,' .th-e inventionprovides that use can be made of the centre cylinder as a gas dischargepipe,-'as.shown inFigureZ;v i *2 A unit using one or other of these twotypes of directional plates is a great improvement on a unit withoutspiral flow since much greater diameters of tube nest can be used atgreatly decreased heights of boiler for the same-total area of heatingsurface. The larger diameter ensures fewer rows of tubes, and betteraccess for cleaning. Abilityto remove both top and bottom plates isvalso very advantageous for clean- In these figures a cylindrical tubeplate I, which has expanded into it inwardly projecting thimble tubes 2,is surrounded "by an outer cylindrical shell 3, to which it is connectedin a water or steam tight manner leaving an annular space 4, between thetwo shells.

The two ends of the cylinder formed by the tube plate are closed in agas tight manner by end plates 5, to which are fitted flanges 6, fortaking the inlet and outlet connections. Spiralled directional plates 1or stepped directional plates 8 are fitted to force the gas to take anup and down spiralled fiow, the inner edges of these plates beingclosely fitted to a removable centre cylinder 9.

I claim:

1.An improved steam generator and water heater for silencing andrecovering waste heat from the exhaust gases from Diesel engines or gasengines, comprising a cylindrical tube plate into which are expandedinwardly projecting tube nest in a manner which provides a graduallyreduced area for the passage of the gas, thus maintaining a consistentlyhigh velocity and turbulent flow.

2. An improved steam generator and water heater for silencing andrecovering waste heat from the exhaust gases from Diesel engines or gasengines, comprising a cylindrical tube plate into which are expandedinwardly projecting thimble tubes, an outer cylindrical shell providingan annular water or water and steam space between itself and the tubeplate, gastight end plates closing the ends of the cylinder formed bythecylindrical tube plate, gas inlet and outlet connections to the thimbletube nest, water and steam connections to the outer shell, a centrecylinder, and adjustable directional plates made in the form of stepsand so arranged between the thimible tubes as to cause the g s t passspirally up and down through the tube nest in ,amanner which provides agradually reduced area for the passage of the gas, thus maintaining aconsistently high velocity andturbulent flow.

3. An improved steam generator and water heater for silencing andrecovering Waste heat from the exhaust gases from Diesel engines or .gasengines, comprising a cylindrical tube plate into which are expandedinwardly projecting connections to the thimble tube nest, Water andsteam connections to the outer shell, a centre cylinder, and adjustablespiralled directional plates so arranged between the thimble tubes as tocause the gas to pass spirally up and down through the tube nest in amanner which provides a gradually reduced area for the passage of thegas, thus maintaining a consistently high velocity and turbulent flow.

4. An improved steam generator and water heater for silencing andrecovering waste heat from the exhaust gases from Diesel engines or gasengines, comprising a cylindrical tube plate into which are expandedinwardly projecting thimble tubes, an outer cylindrical shell providingan annular water or water and steam space between itself and the tubeplate, gastight end plates closing the ends of the cylinder formed bythe cylindrical tube plate, gas inlet and outlet connections to thethimble tube nest,

'water and steam connections to the outer shell,

a centre cylinder, and adjustable stepped directional plates so arrangedbetween the thimble tubes as to cause the gas to pass spirally up anddown through the tube nest in a manner which provides a graduallyreduced area-for the passage of the gas, thus maintaining a consistentlyhigh velocity and turbulent flow, the centre cylinder being arranged sothat an opening is provided into it at the end adjacent to the end ofthe last spiral passage so that the gas can pass into and through thecylinder, and so out of the boiler.

EDWARD FRANK SPAN'NER.

